Automatic air distributing valve for sander systems



Dec. 15, 1931. R. A. LIGHT ETAL AUTOMATIC AIR DISTRIBUTING VALVE FQR SANDER SYSTEMS Filed June 23, 1931 IHHI a .1: (7556 05 M a (7 Patented Dec. 15,1931

UNITED-STATESPATENT OFFICE,

WRALPH A. LIGHT, or eYNwYnANn JOSEPH w. PRICE, JR., or PHILADELPHIA, 2mm

SYLVANIA, ASSIGNORS TO .THE UNITED STATES METALLIC PACKING COMPANY, OF

PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF YENNSYLVANIA' ,VAUTOMATIGYAIB, DISTRIBUTING VALVE FOR SANDER SYSTEMS Application filed'Iune 23,

Our invention relates to sander systems of the gener'alcharacter described in our prior.

I Patent '1,8 00,548, In this patent we have mshown and described :a distributing valve trap sothatwhen air pressure is turned into adaptedto automatically connect the air supply pipe of the'system successively with the clean out and air deliverynozzles of the sand the system a short blast of air will bedelivered through the clean out nozzle and thenthe air is directed into the delivery nozzle of the trap andfin our pending application, Serial No. 529A62, filed April 11, 1931, we have described annnproved construction of the air distributing valve. The object of our present invention is to provide for certain additional improvements in the distributing valve and sander system by providing a distributing valve, which in normal inoperative position will close all ports leading into and out of the distributing'valve casing and which, when pressure air is turned on, will open the admission port into the casing to the passage of V pressure air and successively connect this port with the outlet port or ports leading to the clean out nozzles of the trap and then after closing this port or ports, connect the inlet port'with a porter ports leading to the sand ,delivery nozzles of the trap, the prime object of ourimprovement beingthat the valve in inoperative position, that is to say, when no pressure airis provided, will close'the distributing valve casing to all passages leading ,to or {from it and also to secure astructure wlnch, on the turning on of pressure air to The nature of onr improved constructionv will be best understood as described in connection with thedrawing s, in 'which it is illustrated' and in whichjf I Figure '1 is a diagrammatic showing of a locomotive sander system' of the kind to which our invention applicable.

7 Figure 2 is a sectional-vertical elevation leading to 1931. Serial No 54e,1ea.

showing the construction of our improved distributing valve.

Figure 3 is a view similar to Fig. Qbut v showing a modification of the valve construc-.

tion, and

Figure 4 1s a crosssection on the line ofFig.3. p A indicates the supplypipe through which compressed air from aresorvoir, not shown, is conducted to the distributing valve of the sander system, A indicating a control valve usually locatedin the engineers cab, for ad mitting and cutting oil the air supply to the pipe A. B indicates'the distributing valve receiving air-from the pipe A. and distributing it intimedrelation to the pipes C and D,

connected respectively with the clean out v nozzle and sand delivery nozzle F of'the sand trap, indicated at G. ill-his trap is of a usual construction, having a sand retaining,

bowl G supplied with sandfromareservoir, not shown, through the pipe G and an outlet passage G to which is connected the delivery pipe 'H, which conducts the sand to the trap.

The distributing valve casing and its ap- 'purtenances, as shown in Figs. 2 and 3, are practically identical; It consists of a cylindrical easing B closed at top by ahead I,

and atbottom by a head J which latter head has one or more openings, as indicated at J,

to permit thefree flow of air fromand to this casing. "This head J is ;also'- a central seat, indicated at J I for a coiledspring, indicated at K, I The portion of the provided with valve casing is provided with an inlet port indicated at L, which is connected with the supply pipe A or'thesystein and as shown located outlet ports L has two oppositely one of which is; connected with the pipe 10 the-clean out nozzle E ofthe sand trap and theother one of which would lead to a similar nozzle-in another trap." Spaced from the ports L as shown lower I downin.

th 'val've casing, is anotheroutlet port indi cated at L which is connected through the" pipe D with the sand delivery nozzle F of the 1 trap. As shown, this"passage is bifurcated,

asindicated at 1?, soas to beconnectable with two traps.

formed as shown through the wall of the Mis a passage ofrestricted area,

casing B and connecting with the passage formed in the casing leading to the inlet port at one end and to the top of the cylinder B at its other end. N is a piston fitting in the 5 cylindrical casing B the upper portion of which N forms a piston working in connection with the pneumatic cylinder formed by the upper portion of the casing while the lower portion of this piston, indicated at N forms'a piston valve working in connection with the inlet and outlet ports of the cylindrical casing. The piston N is normally re turned to and helc in the retracted position shown in Fig. 2 by the action of the spring K, which presses against the bottom of the piston and, asshown in Fig. 2, the Valve portion of the piston is provided with a transmission passage for air, which, in this modification, is an annular groove 0, so located that when the valve is in retracted position it does not register either with the inlet port L or with any of the outlet ports indicated at L and L Thelocation and. shape of the groove 0 and the location and shape ofthe inlet port L.

aresuch that the-groove O registers and re- "inains in registry with this port as the valve moves downward and the location of the outlet' ports L are such that as the valve moves downward the groove comes first into registry with the ports L connected with the clean out nozzle, then moves downward out vacuum in the lower part of the of registry with these ports and registers with the port L at the bottom of the downward movement ofthe piston valve.

In the modified structure illustrated in Fig. 3, the piston valve is provided with air passagesformed through the valve instead of around the valve, as in Fig, 2. These passages aremade up of an inlet passage P connected withlateral passages-P located to register with the outlet ports L as the valve moves downward and a third passage P located to register with the port L on the further downward movement of the Mvalve. To prevent any rotary movement of the piston valve, thepiston valve is longitudinally grooved, as indicated at Q in Figs. 3 and 4, and a screw Q is inserted through the casing so that its nd extends into the I groove Q. y

In operation it will be observed that when no pressure air is delivered to the system through the pipe A the spring K, acting on the bottom of the piston and hold the valve to the upper position, as indicated in Figs. 2 and 3, the piston N being also moved up in the upper part of the cylindrical valve casing. The spring is enabled to act promptly upon the valve on the cutting off of air pressure because theportion of the cylinder B in which it is located is in free communication with the atmos phere through a port or ports J so that in moving the val-ve'up it is not opposed by any valve N will force cylindrical chamber. When the pressure air is turned into the supply pipe A it passes first through the restricted passage M into the head of the cylinder B and, acting on the piston head N )resses the valve N downward against the action of the spring K, bringing the channel through the valve, which may be either the groove 0 of Fig. 2 or the passage P of Fig. 3, into registry with the admission port L of the casing. This movement of the valve also brings the groove 0 of Fig. 2 or the passages P of Fig. 8 into registry with the ports L connected to the clean out nozzles of the sand trap or traps, so that a short blast of air of full head will be delivered to the clean out nozzle. The further movement of the valve first closes the ports L and then brings the groove 0 or passage P of Fig. 3 into registry with the outlet port L delivering the full head of pressure air to the delivery nozzle of the trap or traps. When the air is cut off from the supply pipe A the spring K, as already stated, returns the valve to its normal inoperative position, in which it closes all ports leading to or from the valve casing.

It will be understood that the rapidity with which the valve will be shifted on the turning on of pressure air can be regulated by regulating the area of the restricted pa.- sage M and in this way the duration of the short blast to the clean out nozzle is regulated.

Having now described our invention, what we claim as new and desire to secure by Letters Patent, is:

In a sander system comprising an air supply pipe and a sand trap provided with a clean out nozzle and a delivery nozzle and a distributing valve comprising a casing having an inlet port connected to the supply pipe and spaced outletports connected to the clean out and delivery nozzles of the sand trap, a valve movable in said casing in normally inactive position closing the inlet port, said valve being provided with an air channel, which as the valve is shifted in the casing will register with the air inlet port of the casing and successively as the valve continues its movement register with the outlet port connected to the. clean out nozzle and then with the outlet port connected to the delivery nozzle, pneumatic valve actuating mechanism operative under air pressure to shift the valve from its normal inoperative position the pneumatic valve mechanism being connected by a restricted passage to receive pressure air from the air supply pipe and resilient means tending to restore and hold the valve in normally inoperative position.

actuating 1 

